Ive always found it annoying (and rude) when someone does a favor or gives you a gift, then brings it up later (usually more than once).

They aren't just doing it out of the goodness of their heart. They want others to see that as a good person, they feel entitles to pats on the back and more "thank yous". AND theyre also kind of holding it over your head for when THEY need/want something from you. When it comes to people like that I avoid accepting anything from them because Im thinking hmm, whats this gonna cost me? If they dont get what they want, you might get the After all Ive done for you thing, and I just dont want to hear that.

OP, your MIL may have felt happy to do these things, but she needs to dial it back.

My father used to say people like this have a need for constant reassurance. As others have pointed out, they NEED to feel wanted, loved, appreciated, etc.

I have a co-worker like that. Quite honestly, her life is a mess, she's people pleaser, and wants everyone to like her. So she'll do stuff like giving customers what they want, even if it means bending the rules (she's a manager), and so on. While I don't have a problem with one question about her new hairstyle, when she asks 20 times, its like trying to appease a 5 year old.

OP I completely understand, my MIL is the same. She gives DD something I thank her, DH thanks her and now DD is old enough she thanks her. Then MIL tells everyone she meets what she did and expects more thanks you. Bonus points if a week later you get told off because you didn't thank her because she's 'forgotten' you did

Thankfully she lives in another state and we usually talk via skype so I can fake connection issues when it comes up again

OP I completely understand, my MIL is the same. She gives DD something I thank her, DH thanks her and now DD is old enough she thanks her. Then MIL tells everyone she meets what she did and expects more thanks you. Bonus points if a week later you get told off because you didn't thank her because she's 'forgotten' you did

Thankfully she lives in another state and we usually talk via skype so I can fake connection issues when it comes up again

Maybe it's time to get offended that she didn't remember YOUR thank-you to her!